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'84 Coupe Deville rear axle brake line replacement

780 views 7 replies 6 participants last post by  GrandMarquisMan 
#1 ·
I have an '84 Coupe Deville with 71k on it that has developed a leak from one of the rear wheel cylinders. It's been sitting in the garage for a few months hibernating till spring and I noticed the rear brake lines are looking very rusty and should be replaced at the same time. Does anyone know if there's a company that sells just the 2 rear axle lines for this car? (I really don't feel like replacing all 7 lines since I don't have access to a lift, but it looks like they'll all need replacement in the near future anyway) Does anyone know what size flares & lines they are if I just buy two ~3ft sections of preferred lines and bend them myself to fit? I'd like to avoid flaring myself because I'm not very comfortable with it. Thank you
 
#4 ·
If you have time try contacting Inline Tube.
At 1 time I thought they would sell individule lines.
While the replacement should be close and the easiest to fit, it still may need some minor adjustment.
Can be adjusted by hand or fit in place with a rubber mallet.

It's not hard to do with parts store lines.
The PITA part comes in if you discover one side is standard and the other is metric.
The quick fix is sometime they have threaded adapters. Not easy finding & finding the right one.
The bad is the addapter adds length to the fitting where clearance may be an issue.
And is 1 more possible leak.

Another option is to cut the line. Put the correct fitting on the other side. Then flare to fit.
You need a double flare too for this. I recomend a practice run on a spare piece with a new tool.
What's good about this is you can cut the line to fit. As parts store lines come in limited lengths.
To make a lenght too long or short you need to do custom bending.
I don't like to diviate too much from factory bends as you take the risk of interfearance damage.
3/16 bends easy but a cheap bender will make tight & smooth kink free bends.

It's best to go to the store with both ends of the line.
GM liked to make many of the fitting different sizes to avoid mistakes in installation or repair.
 
#5 ·
Thank you for the input everyone. Unfortunately all the parts stores are closed locally in light of the virus (I live on Long Island) so the internet is the only source I can purchase them from. Otherwise I would take the old line and try to match it up. Inline tube does have them, in complete sets only. In the past I was able to order just the preflared lines for an '87 Regal I had from eBay for just the rears for about 35 dollars. I guess I'll just go the complete kit route to make life easier. I've got plenty of time to work on it as I'll be out of work until all of this blows over anyway
 
#6 ·
Measure it as best you can and order like others have said. If you get a competent parts person (I'd even call Summit Racing), they can get you a couple good pieces.

One word of caution, though, is that all lines probably need to be replaced. The brake lines on these cars deteriorate in a similar fashion and time. If one is looking like it might burst, the non-adjacent other corners of the car may be in a similar soon-to-burst scenario. I'd do them all. Good luck.
 
#7 ·
Hello from Southern Nassau! A while back I took my rusted out lines off the car, got a spool of that green polyvinyl brake line (which IMO is much easer to bend) and a tube bender like this: RIDGID 456 44852 Tri-Bender, 1/4-inch, 5/16-inch and 3/8-inch Tubing Bender, Pipe Bender - Tube Cutters - Amazon.com (but from harbor freight) and did my best to replicate the shape. Some on car adjustments had to be made but it did the job.

You'll need a flare set. It was my first time ever flaring anything so I took a few practice tries on scrap pieces. Leave a little extra on the end should you need to cut it off, de-burr and flare again. These are double bouble flares, not ISO flares btw. I got the flare set from Harbor Freight as well. Haven't had a problem to this day (knock wood).
 
#8 ·
Hello from Southern Nassau! A while back I took my rusted out lines off the car, got a spool of that green polyvinyl brake line (which IMO is much easer to bend) and a tube bender like this: RIDGID 456 44852 Tri-Bender, 1/4-inch, 5/16-inch and 3/8-inch Tubing Bender, Pipe Bender - Tube Cutters - Amazon.com (but from harbor freight) and did my best to replicate the shape. Some on car adjustments had to be made but it did the job.

You'll need a flare set. It was my first time ever flaring anything so I took a few practice tries on scrap pieces. Leave a little extra on the end should you need to cut it off, de-burr and flare again. These are double bouble flares, not ISO flares btw. I got the flare set from Harbor Freight as well. Haven't had a problem to this day (knock wood).
Southern Nassau here too! I'm in Bellmore. You're braver than I am. I went with the inline tube kit. I'm not confident to flare all the lines & I didn't want my brake line bends to look like a sad balloon animal. I've done 4 of the 7 lines so far. The one going from the proportioning valve to the rear axle was already replaced. I'll probably end up changing that line this week anyway though. The lines to the master are in very good shape so I'll probably hold off on changing them until the master cylinder needs to replaced.
 
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